Microbe-Metal Interactions: Metabolism and Strategies of Resistance
Elisabetta Bini
Rutgers University
Dept. of Biochemistry and Microbiology

Microorganisms are an essential component of all ecosystems and represent a substantial
fraction of the planet's biomass. They are the base of food webs and have an important impact
on the cycling of metallic elements and the degradation of chemical compounds. In fact,
prokaryotes can change the oxidation state of metals, resulting in their solubilization or
biomineralization. These phenomena are known to occur in the environment and have been studied
in cultures, yet there is still much to be learned about the genetic determinants of metal
transformations. This talk will review the work conducted in my laboratory, which is part of a
broader program of research on cell response to metals, and includes the molecular
characterization of metal responsive genes of microbial species isolated from different
environments. Genomic and molecular tools were used to investigate the mechanisms of arsenic
detoxification in Geobacillus, the utilization of metal compounds as terminal electron
acceptors in Desulfurospirillum indicum for energy production, and to derive a model for copper
homeostasis in the hyperthermophile Sulfolobus solfataricus, which relies on copper efflux and
sequestration. Knowledge of the molecular mechanisms behind the interactions of microorganisms
with metals will lead to a more in-depth understanding of metal transformations in the
environment, and is relevant to the development of strategies for the bioremediation of
metal-polluted sites.